A collet (or collet chuck) is a holding device that forms a collar around, and exerts a force on, a work piece (typically a rod-shaped object). A collet assembly often includes collet segments positioned in a collet chuck body, to center and grip the work piece in a lathe. Typically the collet has a slotted clamping sleeve with a conical portion to clamp a work piece by forcing the collet segments radially in or radially out. The collet fits into a collet chuck which is attached to the face of the spindle or a work surface. One advantage of collets is the precision with which they hold the work piece due to their fixed dimensions.
Collet chucks are known in which a locking screw provides rotational adjustment in discrete increments, for example, by rotating the collet to one or more discrete, regularly spaced stops positioned around the collet chucks circumference. The adjustments are possible in discrete increments due to a key, e.g., a dog point screw, which engages the collet keyway. By relying on discrete stops, such collets are limited to discrete stop positions. Once the rotational position has been fixed relative to a locking screw, it is typically necessary to further rotate the collet in one direction or the other, to tighten it or back it out. Since adjustment is limited to discrete positions around the circumference of the collet chuck body, it is not possible to control the rotational position of the collet.